1. Field of the Invention
The invention pertains to a lock of the type indicated above for use in the doors or hinged lids of motor vehicles. The lock includes a rotary latch which has both a secondary stop notch and a primary stop notch, into each of which a catch can drop. When an open door is closed, a gap sometimes remains, because the catch has dropped only into the secondary stop notch of the rotary latch. The rotary latch then remains in the secondary latching position. To close the gap, motorized auxiliary closing means are used, which act on the rotary latch, moving the rotary latch onward into a final position, in which the catch can drop into the primary stop notch. This final position is called the “primary latching position” in the following.
2. Description of the Related Art
In the known lock of this type (FR 2 768 761 A1), a motor is connected to a gear assembly by a rotating disk, which is used both as an auxiliary closing means and as an auxiliary opening means. The rotating disk is connected by a drive rod to a drive element guided in a connecting link; the drive element turns the rotary latch from its original secondary latching position onward into the primary latching position. This secondary latching position is monitored by a microswitch, which turns on the motor. A sensor stops the motor when the primary latching position is reached. When a control command is sent to open the door, the motor and the rotary disk are actuated and move in the same rotational direction as they do during a closing operation. Numerous components such as link guides and intermediate levers are required so that the motor, which always rotates in the same direction, can be used both to open and to close the door. Such components are subjected to a great deal of wear.
Another known lock (EP 0 109 656 A) has a common electric motor to serve both as an auxiliary opening means and as an auxiliary closing means for a rotary latch, but two different freewheels are required for this purpose. The one freewheel is operational only during the closing process, the other only during the opening process. This is the only way in which it is possible for the cam that moves the latch to be actuated during the closing process while the cam acting on the catch remains at rest. During the opening process, however, the cam belonging to the latch remains at rest, while the cam is actuated to disengage the catch. A complicated and bulky gear assembly is required to operate these two freewheels.